1. Field of the Invention
The invention relates to an adjustable stop for an insert arranged in the main casting or body of a tool having a stop member in the form of a hollow cylinder which is slotted and can be spread by means of an adjustment screw.
2. Background Information
Such an adjustable stop is known, for instance from the published German Patent Application No. 42 43 586 A1. The stop serves in the adjustment of a cutter in the form of a knife guided in a guide slot of a main casting or body of a tool. The adjustable stop comprises a stop member in the form of a hollow cylinder over its entire length, the slotted head of which can be expanded in a radial direction by means of an adjusting screw in order to displace the cutter. For this purpose, the stop member is inserted into a stepped bore provided in the main casting or body, whereby the remaining area of the stepped bore extending to the face of the main casting or body and having a closed circumference defines the adjustment lift.
Due to the different radii of curvature of the stop on the one hand and of the remaining area of the stepped bore on the other, contact is achieved only at points both at the side of the stop facing the cutter as well as on its opposite bearing side facing the main casting. This has the disadvantage that even at low clamping or cutting forces, the stop is overloaded as a result of a high local stress concentration. That in turn can lead to a loss of positioning accuracy and/or stability. Since in addition, the inside threads guiding the adjusting screw follow along the slotted area of an adjustment movement required for a particular adjustment, and consequently positive thread engagement no longer exists in this area, the stability under load of such a threaded connection is only limited, especially at maximum adjustment.